The invention discloses a time frequency analysis method for electric energy error decomposition, which can improve the online decomposition efficiency, can reduce computing time consumption, and can well keep information of original signals in a time scale. According to the time frequency analysis method for electric energy error decomposition, a mode of piecewise linearization between adjacent extreme points is adopted to effectively improve the online decomposition efficiency, time consumed for computation is reduced obviously, and the information of the original signals in the time scale is well kept. The method is applicable to popularization and application in the technical field of gateway metering device state evaluation state evaluation.